Process for precipitating hydrometallurgical solutions by means of an improved precipitant.



G. W. MERRILL. PROCESS FOR PRECIPITATING HYDROMETALLURGIGAL SOLUTIONS BY MEANS OF AN IMPROVED PREGIPITANT. APPLICATION FILED JUNE 7, 1910.

1 0 Patented Oct; 24,1911] 52 91" 0 gwumtoz' l g 5 NET ,HCHARLES W. MERRILL, ed States, and resident iiie d'a county, State of Calit new and useful Imes for ,Precipitating zil' Solutions by Means of tent, of which the folons" and particularly -metallurgical solutions; j Letters Patent of the ,a $60 ,186, granted to me n}; V i 10 ttober, 1908, described 1 (51a eti a sof precipitating and reboy erin'g 'iii ateriitlsfrom solution, which consi adly the precipitant while in mo .th" mixture withoutrest,

or y c'ttwfith the atmosphere to a a ant tnea arat ing the solid fr'oin'fth'e li d insaitl filter he object of this proc 2 5 QSa 11y recipitate and recover materials as precipitants unhlehfmake for increased elli- 30. Howl have discovered as a resultoffthe ram-rear apt tioffof the inventions reiat certain "Zinebearing otherwise desirable to rich as' zinc fume or red 'ess' efiicient and active e'sence of a deterrent P tcaii sedjin art atleast'bytheirwellit'y o oxidation. In processes conducted, including the above "a ticularly'in' the case of amounts of metal o f! result of this is to" deof the precipitation be-" r oiidiminishing the timerstiflr'erp s'se's'to*removethe-de c L s above stated; or

in adding to the'solutiou spa ter-1s by means of the use sseeaisarea with earlier processes.

surfaces of the particles rest-1e activity, and those I at-this oXid must be dis- 1 dum'ngtln prote e of precipitation ibiei it ict' of the 'solutlonand t 1 a m'ent relates, tl1ere-' solution to be treated is' continuously emove this coatimg -pre I .r I

Pat l SerialNo. 565549 vi'ous to the use of by mechanical means.-

The present improved process is conducted substantially'in the same manner as the process described in the above Letters Patent and in substantially any form of apparatus applicable in said process.

In the aforesaid Letters Patent I have described a receiver which is provided for the unprecipitated solution, a receiver or mixer for the precipitant, and suitable devices for the conveyance of said solution to a filter.

'The precipitant may be introduced into the receiver for the unprecipitated solutionby precipitant in the process means of a suitable duct discharge to a sump at the bottom ofthe receiver, ledto any point between said the discharge of said filter.

the 'mixture received into the filter is there or it may be receiver, and

In any event separated into solids which are retained therein andefilue nt liquid or filtrate which is discharged therefrom. I v

The type of apparatus preferablyf em ployed-in conducting the process aforesaid is diagrammatically described in the aceom-' panying sheet of drawings forminga of this application in which- Figure 11s a diagram showing the devices-" for conveying the precipitant to th e solution:

tank, discharging directly into the tanle; "A

Fig. 2, a diagram showing the precipitant:

discharging into the outlet. of the pump, between the pump and: the filter; and Fig.-8,*-=

a diagram showing a discharge into the "su 6. tion pipe of the press Similar letters-refer to similar throughout the several views, I In the diagrams 4U is-the receiveri't'oi' unprecipitated solution I is the a pipe through Y which the. precipitant and emulsifyin q uid is fed, H is the duct throiigh which the:

precipitant is conVeyed'to-the unprecipi tated solution in motion; C is the sac:

and-.D is the discharge pipe of the same F 'is the. filter press, shown in this cas with the'" feed, 1 inlet v at the a top :an'ch is a discharged at the bottom into the receiver E for the precipitated solution by means of;

the pipe G J is the.discharge'pipewfroma the receiver B is the pipe through WlllOlLtll into the. receiver U; 1 2'- In-Fig. 1, A is any! suitable fe d l emulsion of the precipitant be used it may paratus for abrading off the deterrent coating; Fig. 2 shows the tank, or grinding apparatus A, between the pump P and the filter F; Fig. 3 shows the grinding apparatus A between the'pump' P and the receiver U.

For the purpose of grinding the precipitant any suitable grinding apparatus is used.

The ordinary form of ball mill crusher is preferable, andif desired the cyanidsolutienor other liquid which is used to emulsify the precipitant may be mixed with it inthe grinding apparatus.

I do not limit myself to any particular .method of, or apparatus for, conducting the unprecipitated solution from the container in which the dissolution takesplace, to the filter, nor do I limit myself to adding the {-it may be reduced precipitant,

precipitant at any particular point along the duct through which the efiiuent unprecipitated solution passes; nor do I limit myself to'the use of the precipitant in a liquid or emulsified form, but may add it dry.

if desired, a liquid may be 'In practice, added to the precipitant before or after it is introduced into the receiver Z, or if an from the liquid in said filter.

2. The process for preclpitating and recovering material from solution which consists in subjecting a precipitant to machanical treatment for the removal of any deterrent coating from the surface of the particles thereof, adding said precipitant to the duct through which said solution is .being conveyed to a filter, and separating the solid from the liquid in said filter.

-3.. The process for precipitating and recovering material from solution which consists in conveying said solution to a pressure filter, subjecting a precipitant to mechanical treatment rent coating from the surface of the particles thereof, and subsequently forcing the precipitant into said pressure filter with said solution, and separating the solid from the liquid in' said filter.

4. The process for precipitating and recovering materials fromsolution which consists in subjecting a precipitant to mechanical treatment for the removal of any deterfor the removal of any deterrent coating from the surface of the par- .ticles thereof, adding said precipitant to the duct in, which said solution is being conveyed, forcing the mixture into the top of the pressure filter, from the liquid in said filter.

5. The process for precipitating and recovering material from solution which consists in subjecting a precipitant to mechant cal treatment for the removal of any deterrent coating from the surface of .the particles thereof and adding said precipitant to a solution in mot-ion at a point adjacent to the outlet of said solution from a receiver, forcing the mixture through apressure filter, and separating the solid from the liquid in said filter.

6. The process for precipitating and rccovering material from solution which consists insubjecting a precipitant to mechanical treatment for the removal of any deterrent coating from the surface of the particles thereof and adding said precipitant to said solution in motion, conveying the mixture to a filter, and separating the solid from the liquid in said filter, all the while excluding the mixture from contact withthe atmosphere. i

7. The process for precipitating and recovering material from solution which consists in subjecting a precipitant to mechanical treatment for the removal of any deterrent coating from the surface of the particles thereof and adding said precipitant to said solution in motion at a point ad'- jacent to a suction pipe of a pump, thence conducting the mixture to the top of a pressure filter, and separating the solid from the liquid in said filter. I

A 8. The process for precipitating and recovering material from solution which consists in subjecting a precipitant to mechanical treatment for the removal of any deterrent coating from the surface of the particles thereof, adding said precipitant to said solution in motion at \a point adjacent to a suction pipe of a pump, thence conducting the mixture to the top of a pressure filter, separatin filter, all the while excluding. the mixture from contact with the atmosphere. g

9. The process for precipitating and recovering metals from cyanid solutions which consists in subjecting a zinc precipitant to mechanical treatment for the removal of any and separating the solidthe solid from the liquid in said deterrent coating from the surface of the mechanical treatment for the removal of any 130 particles thereof, and adding anemulsion mosses ture from contact with the atmosphere.

11. The process of precipitating and recovering metals from cyanid solutions which consists in subject-inga zinc precipitant to I mechanicat-treatment for the removal of any deterrent coating from the surface of the particles thereof and emulsifyingsaid Zinc preciptant with a liquid iira grinding apparatus, adding a liquid continuously to said grinding apparatus, discharging the emulsion from said grindingapparatus into said solution in motion, conducting the mixture without rest to a filter, and separating the solid from the liquid in said filter.

12. The process of precipitating and recovering metals from cyanid solutions which consists in subjecting a zinc precipitant to mechanical treatment for the removal of any deterrent coating from the surface of the particles thereof and emulsifying said zinc precipitant with a liquid in a grinding apparatus, adding a liquid continuously to said grinding apparatus, discharging the emulsion from said grinding apparatus into said solution in motion, conducting the mixture without rest to the top of the converging pressure filter, and separating the solid from the liquid in said filter.

13. The process for precipitating and recovering metals from cyanid solutions which consists in subjecting a metallic precipitant to mechanical treatment for the removal of any deterrent coating from the surface of the particles thereof, and subsequently adding to the solution said metallic precipitant for precipitating gold and otherunprecipitated metals, conducting the mixture to a filter, and separating the solid from the liquid in said filter.

14. The process for precipitating and recovering metals from cyanid solutions which consists in subjecting a zinc precipitant to mechanical treatment for the removal of any deterrent coating from the surface of the particles thereof, and subsequently adding said zinc precipitant to said solution, conducting the mixture to a filter, and separating the solid from the liquid in said filter.

15. The process for precipitating and" recovering metals from cyanid solutions which consists in subjecting a zinc precipitant to mechanical treatment for the removal of any deterrent coating from the surface ,of the particles thereof, and subsequently adding said zinc precipitant to said solution, conducting the mixture without-restto a filter, and separating the solid from the liquid in said filter.

16. The process for precipitating and recovering metals from cyanid solutions which consists in subjecting a zinc precipitant to mechanical treatment for the removal of any deterrent coating from the surface of the particles thereof, and. subsequently adding said zinc precipitant to said solution, conducting the mixture, excluding the atmosphere therefrom to-a filter, and separating the solid from the liquid in said filter.

17. The process for precipitating and recovering metals from cyanid solutions which consists in subjecting finely divided Zinc to mechanical treatment for theremoval of any deterrent coating from the surface of the particles thereof, adding said finely divided zinc to said solution, conducting" the mixture without restand without contact with the atmosphere to ,a filter, and separating the solidfrom the liquid in said filter.

. 18. The process for precipitating and recovering materials from cyanid solutions which consists in the mechanical abrasion of Zinc precipitant for the purpose of removing any coating on the particles thereof, and precipitating said solution while in motion by said abraded precipitant.

19. The process for precipitating and recovering materials from cyanid solutions which consists in grinding a finely divided zinc precipitant and a liquid in a suitable grinding apparatus, precipitating the materials from said solution while in motion by said precipitant, conducting the mixture Without rest to a filter and separating the solid from the liquid-in said filter.

oHARLEs w. MERRILL.

. \Vitnesses:

lVILLARn PARKER BUTLER, CHARLES ENGEL. 

